Problem
What citrus fruit can produce the most power if it is made into a battery?

Plan

In our experiment, we were trying to find which fruit had the most current and voltage and we made our predictions according to the acidity level of each fruit. We wanted to test which fruit would be best suited as a batter power source.

Hypothesis
If the higher the acidity of the fruits, then the higher the volts and the current it wil produce. In other words, it will have more current and votage rather than a fruit that has a lower acidity level. Therefore according to my hypothesis, I can therefore predict that the lemon will have a higher current and voltage because it has a high citric acid level. Lemons have a pH of about 2 to 3, which is pretty near the extremely sour side on the pH scale.

Materials
  • Multimeter
  • Popcorn Bowl
  • pH Measure Paper
  • Knife
  • Juice Squeezer
  • Alligator Clips
  • Two different pieces of metals: Copper and Aluminum
  • Saw
  • Wood
  • Metal cutter
  • Ruler
  • 50mL beaker
  • Clamp to hold metals
Fruits:
  • Orange
  • Lemon
  • Grapefruit
  • Lime
  • Apple
  • Tangerine
  • Pear
  • Banana


Procedure

Lab 1

  1. Slice each individual fruit enough to get one individual piece of that fruit to weigh as close to 50g as possible (Keep sliced fruits)

  2. Create a holder for the metal electrodes(cardboard) you will stick into the battery so that the distance between each electrode is 1 or 2 cm

  3. Connect your electrode to your multimeter using aligator clips

  4. Stick the electodes into each 50 g piece of fruit and record the voltage and current

Lab 2

  1. Squeeze each fruits until you get 10 ml of liquid (store each liquid in a beaker)

  2. Record the PH of each liquid

  3. Measure the voltage and current of each liquid battery using the electrodes and the multimeter from Lab 1

  4. Record observations



external image 180px-Lemon.jpg
This is a picture of a lemon which we used during our experiment.



File:Citric-acid-3D-balls.png
File:Citric-acid-3D-balls.png

This is an picture of the atomic structure of Citric Acid C6H8O7 The Black atoms represent Carbon, the red atoms represent Oxygen, and the white atoms represent Hydrogen.


external image Citric.jpg
This is also another picture of a atomic structure of Citric Acid, but the difference in the previous picture and this is that there one less hydrogen atom. I therefore believe that it is possible that the extra hydrogen atom may be concealed due to the orientation of the picture.


Qualitative Data
Even though the fruits we used didn't seem powerful at all, a good follow up experiment to do would be to have a larger number of the same fruits and perhaps it will most likely produce a greater voltage and current. In other words, in order for the use of fruits as batteries it is best to have the fruits in large number instead of s single fruit. As for practicallity, it is not a very good idea to have fruits to use as batteries for everyday use because as I said earlier, in order for the current and voltage to be effective, it is best that the fruits are used in large numbers; large numbers would mean inconvience for some people. But the idea of using fruits for batteries can't be totally ruled out, for in the future with the advancement of technology it is possible to be able to use fruits as everyday batteries, although it is still a long process for that to happen.

What can I do to improve our experiment?
If we were to do the same experiment again I would actually test the acidity levels of each fruit to be absolutely sure because we ran out of time to do it. Instead we used the data on the internet as our 'data' for our acidity level results. We can also maybe try to keep the two metals at the same and constant distance during our experiment. I learned that in order to have a fruit that produces a high voltage and current, it is preferable to have a fruit that has a higher acidity than it is to have a fruit which has a low acidity level. The fruit juices were hard to get due to the fact that we had left the fruits on the table which gave the opporunity for the liquid to be evaporated slowly. Maybe it would be best to squeeze the fruit juice immediately out of the fruit once we have taken the voltage and current measurement in its solid form.

Questions?
On the seoncd picture, counting from the top, I am wondering what is the cause of the diffence in the bonds between the atoms? For example, when the red Oxygen atom is bonded with the black Carbon atom its bond consists of two lines, whereas in the other bonds with other atoms the bond is only one thick cylindrical type of bond. What is the reason behind the difference in the bonds?

Source: http://en.wikipedia.org/wiki/Lemon
http://dardel.info/imagesPOV/Citric.jpg
http://en.wikipedia.org/wiki/Citric_acid